The Pentagon has asked Congress for nearly $80 billion to cover the cost of the war in Afghanistan in 2014, a spokesman said Monday.

The request issued Friday for $79.4 billion in fiscal year 2014 is slightly lower than the war funding of $87.2 billion for the current fiscal year, Pentagon press secretary George Little told reporters.

The proposed funding for Afghanistan operations are in addition to a $526.6 billion budget that the Pentagon has already submitted to Congress.

The war funds, officially known as "overseas contingency operations" (OCO), will cover not only daily operations by US forces but also the cost of withdrawing troops and equipment from Afghanistan as planned through 2014.

US officials had previously predicted war funding would drop by a larger margin, and it was unclear whether the cost of pulling out troops and hardware was higher than expected.

There are about 63,000 US troops currently in Afghanistan, and the number is due to drop to 34,000 in February 2014, with all combat forces set to depart by the end of 2014. US and Afghan officials are negotiating a long-term security agreement that would allow for a small American contingent of mostly special forces to remain on the ground beyond 2014.

The Pentagon also asked Congress Friday for authority to shift $9.6 billion in 2013 defence funds to counter the effect of automatic budget cuts.

"The main goal is to limit the impact of sequestration (automatic cuts) on military readiness, particularly training and maintenance accounts," Little told reporters.

"This reprogramming request is in large measure an attempt to shift funds to those accounts."

The Defence Department has had to absorb $37 billion in automatic cuts through the current fiscal year ending in October, a process known as sequestration. Senior officers say the across-the-board cuts have forced the military to scale back training for troops and pilots as well as maintenance work for equipment.

The "reprogramming" of funds would allow the Pentagon to pay for higher than anticipated fuel bills, as well as other maintenance costs, Little said. But he did not specify what programs would lose funding to allow for the shift in money for maintenance and training.